Arbuscular mycorrhizal fungal reads from the roots of 14 different plant species collected along an elevational gradient in Zackenberg, Greenland. Zackenberg_AMF

While arbuscular mycorrhizal (AM) fungi represent an old group of fungi with important functional roles, their global distribution is poorly understood. A particular knowledge gap concerns their distribution and diversity in extreme environments such as the Arctic, and the factors shaping local diversity patterns in these environments. We sampled roots of nineteen plant species in eighteen sampling locations distributed along an elevational gradient in Northeast Greenland, using next generation sequencing (Illumina MiSeq) to identify their root-colonizing AM fungi. We then compared AM fungal presence, richness, and composition among plant individuals belonging to different species and occurring under different abiotic conditions.We identified twenty-nine AM fungal virtual taxa (VT), whereof six represent putatively new VT in 14 of the plant species. AM fungal presence increased with elevation, as vegetation cover decreased and the active soil layer became thinner. AM fungal composition was jointly shaped by elevation and host plant species.Our study demonstrates that the Arctic harbours a relatively species-rich and non-randomly distributed diversity of AM fungi. We found that AM fungi are more common and diverse at higher elevations where conditions are harsher, suggesting that plants can have a high need for beneficial symbionts at extreme environments.